One important task in surgery is end-to-end anastomosis. In the text which follows, this should be understood to mean in particular the surgical connection of blood vessels. However, the techniques described below can in principle also be used for the anastomosis of any hollow organ ends.
In end-to-end anastomosis, stitching is the most frequently used connection technique. However, instead of stitching, which takes a lot of time, the connection can also be achieved in a fraction of the time by using fittings or sleeves. For this purpose, a sleeve which is preferably biodegradable is pushed over each of the two vessel ends. The inner diameter of said sleeve must correspond approximately to the outer diameter of the vessels. The sleeve is in each case pushed over the vessel until the end of the vessel protrudes slightly out of the sleeve. The end of the vessel then has to be turned over around the end of the sleeve so that the sleeve is secured and the inner side of the vessel, the tunica intima, is facing outwards. The two sleeves are then pushed into a third fitting and are fixed in the latter in such a way that the inner sides of the two vessels make contact with one another around the entire circumference. This is necessary in order for the two vessel ends to be able to grow together.
During this procedure, the work of the surgeon can be facilitated by various auxiliary means, for example by using devices which hold and clamp the ends of the blood vessels, which hold fittings and help to align these with one another in the axial direction, which make it easier to push the fittings together, or by using a device which assists and facilitates the process of turning the ends of the blood vessels over around the ends of the fittings.
Many auxiliary means for the anastomosis of vessels have already been known for decades. U.S. Pat. Nos. 4,474,181 and 4,624,255 disclose a device which consists essentially of a ring having a diameter larger than the outer diameter of the blood vessel. The vessel ends to be connected are firstly stitched together at least at three points. The ring is then pushed over the stitching area. Using the threads of the stitches, the vessel is widened to the diameter of the ring and is fixed to the ring in this position. As a result, the inner sides of the two vessels are brought into contact with one another. U.S. Pat. Nos. 4,016,883 and 4,165,747 contain examples of clamps, especially for blood vessels having a small diameter. U.S. Pat. No. 4,165,747 moreover proposes clamps which are arranged in a displaceable manner on a common rail. In this way, the blood vessels can be simultaneously clamped and can be fixed in position relative to one another; this makes it easier to stitch them together.
Further devices which ensure the mutual axial alignment of the vessel ends and filtings are described in U.S. Pat. Nos. 1,151,300, 2,940,451 and 3,048,177. In all cases, at least one vessel end must be turned over around a sleeve prior to the connection operation so that the inner sides of the two vessels make contact with one another after being joined.
Unlike the abovementioned patent specifications, U.S. Pat. No. 2,453,056 describes how the turning-over of the vessel ends is achieved, namely by using tweezers. It is known that it is very difficult to turn vessels over using a number of pairs of tweezers, and this process sometimes requires more than one person. Even if the surgeon is assisted by a mechanical device which is able to hold and guide a number of pairs of tweezers or grippers in a suitable manner, there is still the risk that the vessel ends will be damaged during the manipulations.
U.S. Pat. No. 2,453,056 demonstrates that the use of sleeves or fittings as auxiliary means for anastomosis has already been known for a very long time. Patents U.S. Pat. Nos. 3,221,746, 3,254,650, 3,254,651, 3,774,615, 4,366,819 or 2004/0199189 A1 also propose the use of fittings.
Various auxiliary means have also been developed for turning the vessel ends over around the end of a sleeve. GB 1413191 proposes a number of spikes which are formed on the outside of the sleeve and can be moved in the axial direction. They have barbs pointing outwards and protrude slightly beyond the end of the sleeve. The edge of the vessel, which has previously been pushed through the sleeve, is pulled and respectively pushed onto the barbs by means of tweezers.
The spikes are then retracted. The vessel end is thus pulled over the end of the sleeve.
U.S. Pat. No. 2,940,452 proposes the use of an elastomer membrane. The latter is pulled taut over the end of a tube. A cylindrical piston with a conical end is then pushed forward through the interior of the tube until the membrane has a conical bulge. In this position, the piston with the membrane pulled taut over it is pushed into the end of the blood vessel protruding beyond a sleeve and then is pressed against the sleeve. The outer tube is then pushed in the direction of the vessel. In the process, the membrane is placed around the end of the sleeve, and with it the protruding part of the blood vessel.
U.S. Pat. No. 3,180,337 describes a similar device, but without the membrane. A cylindrical piston with a conical end is again used. The cylindrical part of the piston is surrounded by an axially displaceable tubular part made of elastic material. Firstly, the conical end of the piston is pushed into the end of the blood vessel protruding beyond a sleeve and then is pressed against the sleeve. The aforementioned tubular piece is then pushed over the piston in the direction of the blood vessel. The tubular piece firstly upsets the protruding end of the blood vessel, then widens together with the end of the blood vessel, and finally both are turned over around the end of the sleeve.
U.S. Pat. No. 2,779,996 describes an elastic ring as an auxiliary means, which is pushed into the interior of the protruding part of the vessel end. After being inserted, the ring—and thus also the protruding part of the vessel—is widened by means of compressed air, and in this way the protruding part of the vessel end is turned over around the sleeve.
The device according to U.S. Pat. No. 3,040,748 is similar to the auxiliary devices in U.S. Pat. Nos. 2,940,452 and 3,180,337. It uses a cylindrical piston with a conical end in a known manner. A thin tubular piece made of an elastic material is pulled on behind the conical head. The rear end of this tube has a bead. It is held by a further tube which can be displaced in the axial direction, and is already widened. In a known manner, the piston with the conical end is pushed into the protruding part of the blood vessel and then pressed against the sleeve. This operation is assisted by a fluid which is pumped through the tip of the conical piston head into the clamped vessel. The fluid flows between the vessel and the piston and also through the tubular piece made of elastic material, and thus makes it easier to push the vessel end onto the tubular piece. Once it has been pushed on, the flow of fluid is stopped. The outer, displaceable tube is then pushed in the direction of the sleeve. It takes with it the elastic tubular piece—and thus the vessel end pushed over the latter—and turns both of these over around the sleeve.
U.S. Pat. No. 4,055,186 describes a press-fastening system for joining two parts of an intestine. Attached to both parts of the press fastener is a concentric ring which is mounted in a flexible manner in the axial direction. The rings have an outer diameter which is somewhat smaller than the inner diameter of the intestine parts to be connected. The press-fastener parts with the rings are pushed into the ends of the intestine parts and then the latter are turned over inwards around the rings. There is no description as to how this is to be achieved. The press-fastener parts are then joined and latched together. Thanks to the flexible rings, the two intestine parts are pressed against one another with a defined force.
All the aforementioned devices for the anastomosis of blood vessels have certain drawbacks with regard to handling or their function. The object of the invention is therefore to find an improved device for anastomosis without the drawbacks of the prior art.